The field of data communication has grown with the pace of new data routing equipment, switches, and techniques that have enabled all types of data to be transmitted over wide area networks (WANs) faster and in more reliable ways. Manufacturers are competing to introduce faster data routers and better methods for synchronizing and integrating state-of-the-art equipment provided by a variety of competitors. Newer protocols for transporting data are also being developed and refined.
One of the more recent protocol standards initiated by the Internet Engineering Task Force (IETF), which is a standards organization well-known in the art, for routing data more efficiently through a network, is known as multi-protocol-label-switching (MPLS). MPLS is an IETF initiative that enables traffic engineering over dedicated paths set-up through an MPLS network. Integration of network transmission data specific to more than one network protocol layer enable the paths, also known as label switched paths (LSPs). LSPs may be manually configured or, as in many cases, created as needed by intelligent routing software.
Creation of LSPs has given administrators more control in routing data around link failures, bottlenecks, or other trouble spots in a network topology. Further, MPLS can be used to manage different types of data streams routed over different LSPs. Quality of service (QoS) parameters can be set-up over specific paths such that high bandwidth data, such as streaming video, travels over a specific LSP, reducing latency from end to end.
Packets entering into an MPLS network are assigned labels by a first router of the MPLS network known as label edge router (LER). The LER determines to which existing LSP a particular type of packet will be assigned, and labels all of the same type packets for the same LSP. Once labeled packets arrive at a router of the MPLS network known as a label switch router (LSR), the labels can be switched from ingress value to egress value and forwarded on without requiring extensive look-ups or complete header processing. Once the packets arrive at a last LER before exiting an MPLS network the labels are stripped from all of the packets. Much information is publicly available on MPLS, therefore high-level details concerning its various applications, of which there are many, will not be provided in this specification. MPLS can be implemented in point-to-point protocol (PPP) and Ethernet implementations, SONET applications and so on.
In prior art, if a router operating in a LSP in an MPLS network fails in terms of MPLS function (setting up the LSPs using RSVP or LDP), then the entire LSP is compromised and data must be re-routed through another existing or a pre-configured backup LSP. Typical fault tolerance for an existing LSP in an MPLS network involves automatic protection switching (APS) or other similar protocols. Therefore, if a router in an LSP fails, a pre-configured LSP backup, if available, must be activated to continue in place of the former LSP. However, switchover must be completed within a 50 ms time window to meet APS requirements. This procedure can be quite tedious because there may be many hundreds of active LSPs through any given MPLS-based network, and the time requirement is often missed.
A data router known to the inventor uses a distributed processing architecture to manage packet routing. The router is termed by the inventor a Terabit Network Router (TNR), which was developed to improve data routing efficiency and cost-effectiveness in general. The distributed processing architecture comprises redundant cabinet-mounted apparatus, each of which comprises line cards that interface between internal router domain and the external connected network, fabric cards that comprise an internal data packet routing network within the router itself, and control cards that provide control routines, messaging, internal data distribution, and in some cases special packet processing duties. Further, in a preferred embodiment of the present invention, two of the control cards, known as the Global Master Control Card (GMCC) and backup-GMCC, provide additional control functions over the whole system.
Each card in a TNR typically has its own on-board processor and memory. Line cards also have physical interfaces comprising ingress/egress ports for transferring data. Prior art routers employing a single or at most, a few processors cannot be protected in terms of an MPLS server failure, because all of the work of the server involved typically executes on one processor.
It was described above that the standard of 50 ms for switchover to a backup LSP must be adhered to for APS protection to be successful. If a switchover process times out or fails over, the backup LSP will not exhibit a successful handshake and transmission will fail. It has occurred to the inventor that a distributed processor router can overcome some types of capability failure by virtue of its distributed architecture and internal networking capabilities involving individual components of the architecture.
What is clearly needed is a method and apparatus for a distributed processor router that allows MPLS server failure to occur within the router without exempting the router from MPLS service or compromising any existing LSPs that include the router as an LSR or LER.